been doing a ton of research on adjusting skimmers, looks like yours is running a little wet. i was having a similar problem and i dropped the water level a little and tightened the air intake and mine is running beautiful.
wet to dry skimming is a preference that the tank owner has to choose. truly wet skimming pulls out more stuff faster as the water surface tension needed to get the foam into the cup is lower. dry skimming will get you darker stuff in the cup but will leave more in the tank. so...... if i do sps i wet skim if i do any other corals i will usually dry skim to leave more particulates in the water.